Ukraine's armed forces said on Thursday they had liberated more than 20 localities in Kharkiv from Russian occupation since the start of the week, as Kiev's counter-offensive shows signs of success.
"At this point, our soldiers have penetrated up to 50 kilometres deep into the enemy's defence lines," general staff representative Olexiy Hromov told the press on Thursday.
He said "purges from the enemy" were continuing in the liberated areas, although his statements could not be independently verified.
Ukrainian units also pressed forward up to 2 kilometres near Kramatorsk in the eastern Donetsk region. They managed to push back Russian forces near Sloviansk by up to 3 kilometres, and freed the village of Oserne.
In the southern Kherson region, Kiev's forces pushed back Russian troops by 2 kilometres and by up to several dozen kilometres in some areas.
The spokesperson said Ukraine has gained more than 700 square kilometres of territory in total in the southern counter-offensive, launched last month.
He described other parts of the front as being in a "difficult, but not critical situation," with Russian units continuing to carry out attacks.
Later, Ukrainian President Volodymyr Zelensky said Ukrainian troops had also retaken the district town of Balakliya in eastern Ukraine.
However, the administration appointed by Moscow to oversee occupied areas around Kharkiv claimed that Balakliya and the village of Shevchenkov remained under Russian control.
Russia launched the war on Ukraine in February, with fighting now concentrated in the east and south, with the lines fluid amid Ukraine's counter offensive.
Earlier, Russian troops said they were taking women and children out of the town of Kupyansk, an important transport hub in Kharkiv.
"We are simply forced to ensure the evacuation of the population - at least women and children - because the city is exposed to missile attacks by Ukrainian military units," the head of the Russian-appointed military administration, Vitaly Gantshev, said, according to the state news agency TASS.
Kupyansk is at the intersection of several railway lines and main roads. It is considered strategically important as it is on the supply route for Russian troops marching towards the Donbass region.
In Kiev, US Secretary of State Antony Blinken pledged $2 billion dollars in fresh aid for Ukraine and other countries in the region during an unannounced visit to the capital.
He was meeting Zelensky, the president's spokesperson, Serhiy Nikiforov, told Ukrajinska Pravda news site earlier.
Blinken was travelling accompanied by journalists from US broadcaster CNN who reported that he had met Ukrainian Foreign Minister Dmytro Kuleba and visited a children's hospital in the capital.
It is Blinken's second visit to the city since Russia attacked Ukraine in February and aims to show Washington's support.
The money he pledged is to be divided between Ukraine and 18 Eastern and Southern European countries.
That sum followed an announcement that Ukraine will receive another $675 million in military aid from the US to help in its war against Russia, US Defence Secretary Lloyd Austin told a meeting held at a US base in Ramstein, Germany.
Austin had invited the members of the Ukraine Contact Group to a conference at the base, which was also attended by German Defence Minister Christine Lambrecht and NATO Secretary General Jens Stoltenberg, among others.
In further support, Germany and the Netherlands said they would train Ukrainian soldiers in mine detection, clearing mines and explosive devices hidden as booby traps, Lambrecht and her Dutch counterpart Kajsa Ollongren said.
In a broader assessment of the war so far, Russia's invasion of Ukraine is a military failure, with Moscow's forces only achieving "minor tactical success in various parts of eastern Ukraine," according to US Chairman of the Joint Chiefs of Staff Mark Milley.
"But so far, Russian strategic objectives have been defeated," Milley told the backers of Ukraine.
"That's due to their failures. And also due to the bravery of the ... Ukrainian military, the bravery of the Ukrainian people and the support of the countries that were at the Contact Group today."
"Russian lines of communication and supply chains are severely strained," Milley said, adding that Moscow was having "great difficulty resupplying their forces and replacing their combat losses."
Meanwhile the leader of the pro-Russian separatists in Donetsk, Alexander Khodakovsky, openly contradicted one of Moscow's justifications for the war, saying he has found no evidence that Kiev planned to attack Russia.
"Ukraine has been preparing for a defensive war," Khodakovsky said in on his Telegram channel, referring to documents captured by his troops after seizing Ukrainian positions. He said he had not come across a single tactical document that laid out acts of aggression.
Russia attacked Ukraine on February 24, with the Kremlin saying its invasion was to pre-empt an attack by the Ukrainian army on the parts of the Donetsk and Luhansk provinces that broke away in 2014. Kiev was also planning to attack the Crimean peninsula, which was annexed by Russia in 2014, Moscow claimed.
Ukraine has repeatedly denied the accusations.
